Electric switch



Jan. 31, 1933. H, P, PINKHAM 1,895,817

ELECTRIC SWITCH Filed Jan. 19 1931 Patented `lan. 3l, 14933 UNITED STATES PATENT OFFICE HENRY P. PINKHAM, F WOLLASTON, MASSACHUSETTS, ASSIGNOB TO CONDIT ELEC- TBICAL MANUFACTURING CORPORATION, OF HYDE PARK, MASSACHUSETTS, A COR- PORATION OF MASSACHUSETTS ELECTRIC SWITCH Application led January 19, 1931.

This invention relates to safety enclosed electric switches especially adapted for the control of small power circuits, vas motor circuits, and the like.

Switches of this type are usually electrically operated with push button control for closing and opening the switch to start and stop the motor and the control push buttons may be located at a considerable distance from the switch which they control. It is therefore desirable to provide some meansl for completely isolating the motor control switch from .the power supply when it is necessary to make repairs on the switch or the load circuits controlled thereby.

It is an object of this invention to provide an improved arrangement of motor circuit switch by which the motor control switch can be completely disconnected from the power line, whereby repairs to the control switch or to the motor and the Aapparatus Awhereby the cover remains locked until the disconnecting switch has been opened and whereby the disconnecting switch cannot be closed until the cover has been closed.

A further object is to provide an enclosing casing for a main switch and a disconnecting switch as above described having `simple means r:tor locking the disconnecting .switch in either open or closed position.

A still further object of the invention is to provide locking means which is connected with the switch operatingr mechanism of the disconnectingr switch and .is operative positively both intoand out of locking position -by lthe closing yand opening movements of said mechanism, thus preventing failure of the .interlock `by sticking of the locking mechanism.

A'yet -ifurther object is generally to im- Serial No. 509,718.

prove switches for the control of small power .c1rcu1ts.

Fig. 1 is a side elevation of the circuit controlling and disconnecting switches embodying the invention.

Fig. 2 is a front elevation ot' the operating mechanism of the disconnecting switch of Fig. l, rthe cover lbeing partly broken away.

Fig. 3 is a sectional detail of the operating mechanism of Fig. 2. A

Fig. 4 is a detailed showing of the interlock between the casing cover and the operating mechanism for the disconnecting switch, the parts being shown in switch closed position.

F ig. 5 is a detail of the interlocking mechanlsm in switch open position with the cover open.

Fig. 6 is a perspective view of the locking plate.

Fig. 7 handle.

As herein shown the switching apparatus embodying the invention includes an electrically operated circuit interrupter or switch A, which is adapted to be remote controlled, and a manually operable motor circuit disconnecting switch B, which is adapted to be connected between the interrupter A andthe power source, whereby to completely velectrically isolate the motor circuit and the interrupter when the switch is opened. Said switches are ycontained in a common enclosing casing having complemental front and back casing sections 10 and 12 respectively,

is a detail of the switch 4operating .the front section 10 of which is hinged at one side to said back section and constitutes a removable closure -or the open front of said back section whereby to permit access to both switches when the casing is open. As here shown the casing preferably is relatively tall and narrow and the switches A and B are located one above the other therein.

The invention is particularly concerned with an improved interlocking means which governs the operation of the manually controlled operati-ng mechanism of the discon- -necting switch and the opening of the cover means is also so arranged that access to the interrupter cannot be gained while it is under potential.

Said disconnecting switch B is supported on an L-shaped supporting plate or bracket 14 which includes a back plate 16 which is secured removably by ymeans of key hole slots 16a and screws 17 onto theinner face of the rear wall12afof said backcasing section 12. Said bracket has an angularlyerelated forwardly-extended side portion 18 which overlies the right hand side wall 125 of said back casing section as viewed in Fig. 2. Said side portion 18 is terminated Vflush withthe front edge of said side wall and thereat is provided with a'fronty inturned flange`20 which lies parallel with the back portionk16 of said bracket. Said disconnecting switch includes a switch frame hav-ing left and right hand parallel side plates 22, of which the right hand plate is shown in' Figs. 2 and 3, which are provided with rear oppositely and outwardly reflexed flanges 24 by which they are secured removably to the back portion 16 of said bracket by means of screws 26. Said side plates are secured together in spaced relation at their upper endsV by means of a "horizontal insulating plate 28 and are fixed in spaced relation at their lower ends by means of a vertical insulating plate 34 which is secured to front inwardly directed flanges thereof by means of screws 36. Said insulating plate 28 is provided on its bottom face with a plurality of spaced and fixed contact Vmembers 38 which are adapted to cooperate and projects beyond the right hand side plate Vto provide a cylindrical handle attaching portion 45. Said mechanism is such that by1 a substantially 90"V rotationof said operating shaft 44 in opposite directions it effects the opening and closing movement-of said movable contact members. An operating handle 46 is provided for opening and closing said disconnecting switch manually. Said handle is shown most clearly in `Fig. 7, and includes Va horizontal tubular section 48 which is adapted to be removably received on the cylindrical end 45 of said Operating shaft 44 and is held in position thereon by suitable means asa resilient Wire clip 50 which passes removably through said handle section 48 and through said shaft whereby to pin the handlerernovably to the shaft. Said handle -is provided vwith Yan outstanding'- flattened portion 52 which extends outwardly through an enlarged circular opening 54 in the side Vwall 18 of said bracket and projects beyond 10 of the enclosing casing from being opened unless. the disconnected switch'B has first been opened, and the closing/of the switch except when the cover is closed, zwhereby to prevent improper access tol andV operation of both switches. Said meanscomprises. interlocking mechanism that at certain times interconnects the cover and the shaftof the disconnecting switch. Said mechanism includes a hub which iscarried by and is rotatable in the extension 18 of the supporting bracket in concentric relation with the switch shaft 44 and operating handle; and is actuated by said handle, Said hub is comprised of cylindrical inner and outer flange plates 58 and 60 which are larger than the opening 54 in said bracket and which overlie said opening on opposite sides of said'bracket, and an intermediate hub plate 62 whichv is journalled in said opening 54. Said plates are permanently secured together in co-aXial relation by means of rivets 64 and 65 and thus constitute a flanged hub which is held against axial displacement but is freely rotatablein the bracket 14. Said plates are provided with aligned axial passages 66 therethrough through which the horizontal portion 46 of the operating handle isextended, the passage in the outer plates preferably being somewhat elongated to accommodate the flattened portion 52 of the handle. Said outer `plate 60 as shown most clearly in Fig. 4 Vis provided with aV pair of spaced struck-'out ears 68 which engage opposite sides of the operating arm53 of the handle, thus to connect said handle and said hub removably together for conjoint rotary movement. Y

The rivet 65 which secures the plates 58, 60 and 62 of the hub together is provided with an enlarged inner shoulder 70 which provides a pivotal support for a vertical locking plate 72. Said locking plate, as shown most clearly in Fig. 6, is generally rectangular in shape and has atits lower end a horizontally-elongated slot 7 4 in which the shoulder 70 of the rivet 65 is loosely located, the head 7 6 holding the plate secured against detachment to the hub. Said locking plate 7 2, which is adapted to be vertically reciprocated by rotary move# and closing movements of said operating' mechanism is provided with an upper offset portion 7 8 which lies closely alongside and is held in position by the forwardly extended portion 18 of said bracket, as shown most clearly in Fig. 2. Said offset portion is provided with an inverted L-shaped slot having the long vertical portion and a shorter horizontal and rearwardly extended portion 82; and a pin 84 which is carried by and is rigid with the side portion 18 of said bracket is received loosely in said slot. The length of the vertical portion 80 of said slot is arranged to be commensurate with the stroke of said locking plate as it is reciprocated between its extreme positions corresponding to the open and closed positions of the switch. The lower edge 83 of the horizontal portion of said slot constitutes a locking shoulder hereinafter to be described. Said offset portion 78 is further provided with an open top marginal slot 79 in its front edge having a long rear abutment face 85 and a shorter front abutment face 86 which constitutes a locking shoulder. A pin 88 is carried by and projects inwardly from the side wall of the cover 10 in position to engage the front edge of said locking plate and enter said marginal slot as will hereinafter be described to lock the cover closed in the switch closed position of the mechanism. Means are provided which constantly biases said locking plate into its foremost position, as shown in Fig. 5, in which the pin 84 and the shoulder 70 of rivet 65 are disposed in the rearmost portion of the slots 82 and 74 respectively. Said means includes a thrust arm 90 which is pivotally connected with said locking plate at 92 and which extends rearwardly thereof and has a reduced rectangular end portion 93 which projects loosely through a rectangular slot 94 in the outstanding ear 96 of an angular clip which is secured to the inner face of the portion 18 of said bracket. A compression spring 98 is disposed on said reduced portion 93 and bears against the shoulder 100 formed by said reduced portion 93 and against said ear 96 whereby constantly t0 urge said arm and the locking plate forward in the casing.l

Means are provided to limit the movement of the operating mechanism in a switch opening and closing direction. Said means, as shown most clearly in Figs. 1 and 4, includes a pair of spaced stop members 102 located about the periphery of said opening 54 and which are secured as by riveting'to the outer face of the portion 18 of said bracket just beyond the margin of the outer plate 60. Said stops are provided with angularly outstanding ears 104 which are adapted to be engaged by a radially outstanding arm 106 which is carried by the outermost plate 60 of said hub.

VSaid arm 106 andthe ears 104 of said stops are provided with aligned holes to receive the hasp of'a padlock, not shown, so that the switch handle can be locked either in its closed or open position. The right hand side wall of the back casing portion 12 in the vicinity of the operating mechanism is provided with a cutaway portion 108 which is sufficiently large to permit the bracket 14 and its assembled operating mechanism to be moved horizontally into and out of position without interference from the casing. Said bracket 14 is also rovided with a horizontal rearwardly-exten ed notch 110 which is arranged to receive the cover pin or projection 88 therein when the cover 10 is closed.

A latch 112 is carried by the outer side wall of the back casing portion 12 and is provided with a forward offset portion 114 which overlies the side wall of the front cover l0. Said latch is provided with a vertical notch 116 in its lower face which engages an outstanding lip 118 of a bracket 120 carried by said cover. Said latch 112 and bracket 120 are provided with parallel outstanding ears 122 and 124 having aligned passages 126 therethrough to receive a padlock by which the cover can be locked in closed position if desired.

In the position of the mechanism shown in Fig. 1. the switch B is open and the locking plate 72 is in its lowermost position in which the pin 84 is disposed in the top of slot 80 and the cover pin 88 is above and free from interference with the locking shoulder 86. Said pin 88, however, is in engagement with the abutment face 85 and constitutes a fulcrum on which the plate 7 2 rests. The thrust arm 90 acts in a line which includes, or is slightly below, the pin 88 in this position of the locking plate and consequently the locking plate will be held in the position shown in Fig. 1, in which the pin 88 is disposed in the forward end of the horizontal portion 82 of the L-shaped slot and directly above -the vertical portion 80 thereof, and the shoulder rivet 70 is disposed in the rearmost portion of slot 74. In this position it is possible to close the interrupter, after which, as shown in Fig. 4, the cover pin 88 is disposed behind the locking shoulder 86, thus to prevent opening the cover 10.

The locking mechanism is also arranged to lock the switch mechanism of disconnecting switch B in the open position Whenever the cover is open and until the cover has again been closed. The position of the parts with the cover open, is shown most clearly in Fig. 5, in which the cover pin 88 has been removed from engagement with the abutment face 85 of the locking plate and the locking plate, under the influence of the thrust arm 90, has moved about the shoulder 70 which now constitutes its pivotal support into its foremost position in which the pin 84 is disposed at the rearmost end of the horizontal slot 82. In this kposition ofthe locking plate,

las`

the latch 112 Amaintains the cover closedk against'fthe spring pressure exerted against the pin 88 thereof by the .thrust arm 90. If, however, the latch 112 is elevated to release the cover, by the opening movement of the cover, the switch is Vlocked in open. position. The pressure-of the spring 98 can be sufficient, upon release of the latch 112, to move the lockingplate torswitch locking position and simultaneously to push open the cover. t will also be evident that when the cover is in closed position and the vswitch is closed that the, cover is securely locked in closed position. Furthermore by the provision of a locking plate .which is positivelyv operated into both its switch locking andcover locking positions greater security is afforded than has been possible with prior devices wherein thelocking plate was positively operated at most in oney direction only.

The inturned ange 2O of bracket 14, which for clearness is broken away in Fig. 2, conceals and protects the locking plate 72 against careless `or accidental operation by an operative to release theV switch mechanism for closing movement when the cover 'is open. Various changes in the construction and arrangement of the parts may be made withoutdeparting from the scope of the invention. Y I claim:`

r 1. In an enclosed electric switch, a switch casing Yprovided with a movable cover, a

ing and closing movement of said switch, said locking member having a locking shoulder, a

fixed abutment adapted in one position of said locking member to engage said shoulder and in another position to be free therefrom, means constantly biasing said locking member into engagement with said abutment, and a' cooperating abutment carried bythe cover arranged to engage said locking member in the closed position of the cover and move said locking shoulder free from said abutment. Y

`2. In combination, a switch casing having a movable cover, a switch in said casing having a movable `switch element, a switch operating member for said movable switch element, a locking plate pivotally connected with said switch operating member having a locking shoulder, a fixed abutment for engaging said locking shoulder to hold the switch operating-member in a predetermined' position',

an. abutment `on the cover for engaging the lockingV plate in the final' closing movement of the'cover to shift said locking plate and throwthe locking shoulder thereof free of said fixedV abutment.

y 3. In combination, an'enclosing casing for an electric switch having a movable cover, a switchin said casing having a movable switch element, a. switch operating handle connected with said movable switch element, a locking n Vsaid switch operating handle.

Ll., In combination, a switch enclosing casing having a movable cover, a bracket secured removably in said casing, a switch mounted on said bracket having a. switch operating element, a switch operatinCr handle operatively connected with said suiitch element, means carried by said bracket having an operative connection with said switch operating handle arranged to lock said switch operating handle in switch open position, ,saidl means including a reciprocable locking plate having a locking shoulder, a stop carried by said bracket arrangedV in one position of said plate to lengage said shoulder, means to bias said locking plate into the aforesaid locking positiornand means associated with said Vcover for engagingv said locking plate in the finalclosing movement of said cover to. move said locking plate against its bias and throw the locking shoulder thereof free of said fixed stop, whereby to'permit closing movement of the switch.

[75. ln combination, a switch enclosing casing having a movable cover, a bracket removably located in said casing, a switch mounted on said brackethaving a switch operating shaft, an operating handle operatively connected withy said shaftmeans carried by said bracket for locking said operating handle in the switch open position thereof, said means including a reciprocable Vlocking plate having an operative connection with said handle, saidlocking plate having a locking shoulder, astop member carried Yby said bracket in position to engage said shoulder in the open position of the switch. means biasingV said plate into engagement with said stop member, and means operative in response tothe final closing movement of the cover to engage said locking plate and throw the locking shoulder thereof free of said stop.,

:6. Incombination, a. switch enclosing casyhaving a movable cover, a switch in the casing, operating ymechanism for the switch, a. reciprocable locking plate operated by said vmechanism having "a locking shoulder, an abutment 'arranged in one position of said -plate to venga e said shoulder to hold said operating mec anism lin predetermined position, means constantly biasing said plate into lockingengagement with said abutment, and means operative during the final closing movement of the cover to shift4 said plate against said bias and move said locking shoulder free of said abutment, whereby to viper-"mit the operation of said switch operating mechanism.

7. In combination, a switch enclosing casing having a hinged cover, a removable switch frame mounted in the casing, a switch snpported by said frame including station- 'ary and movable contact members, operating mechanism lifor the switch, a reciprocable 'locking plate carried by'said frame 'and'having apos'itive operative connection with said operating mechanism, said locking plate havingwa horizontal locking shoulder and a vertical locking shoulder, an abutment carried byvsaid frame for engaging vsaid horizontal locking shoulder in the 'switch open position of said flocking plate, a second abutment carried b 'the cover arranged to engage said vertioa locking shoulder in the switch closed position of said plate, means constantly biasing lsaid locking plate into position to engage said first abutment member when said cover is open, said second abutment member arranged in the closed position of said cover to enga-ge and move said locking plate against its bias into the position wherein said horizontal locking shoulder is free from said first abutment.

8. An electric switch mechanism comprising an enclosing casing having an opening thereinto, a door for closing said opening, a Switch in said casing including stationary and movable contact members, operating mechanism for said movable Contact member-,an operating handle, a locking plate operatively connected with said mechanism to move between switch open and closed positions, said locking plate having a locking shoulder, a fixed abutment for engaging said locking shoulder, means to biassa-id locking 'plate Iinto a position to engage said abutment, and mea-ns connected with said door having a part extended into position to engage said locking plate in the final closing movement thereof to move said locking shoulder free from said abutment, whereby Vto permit switch closing movement of said operating handle.

9. An'electric switch mechanism comprising an enclosing casing havingr an opening thereinto,l a door for closing said opening, a switch in said casing including stationary and movable contact members, operating mechanism for said movable Contact member, an operating handle, a locking plate operatively 'connected with said mechanism to move between switch open and closed positions, said locking plate having a locking shoulder, a fixed abutment for engaging said locking shoulder, means to bias said locking plate into a position to engage said abutment, and means connected with said door having a part extended into position to engage said locking plate in the nal closing movement thereof vto move said locking shoulder free from said abutment, whereby to permit switch closing movement of said operating handle, said locking plate also having a second 'locking shoulder for engaging the extended part of said door in the switch closed position of said plate whereby to prevent opening movement of said door.

10. An electric switch mechanism comprising an 'enclosing casing having an opening, a removable cover for said opening, a switch in said casing, switch operating mechanism including an operating handle located externally of said casing, a reciprocable locking plate having a pivotal connection with said switch operating mechanism and adapted to be operated positively between two positions corresponding to `the switch closed and switch open positions of said mechanism, said plate having a slot therein, a fixed stop member adapted to enter said slot in the switch open position of said plate, means which constantly biases said plate in a direction to engage said stop, and means responsive to closing movement of said cover which moves said plate against its bias to disengage said stop, whereby to liberate said operating mechanism for switch closing movement. l

11. An electric switch mechanism comprising an enclosing casing having an opening, a removable cover for said opening, a switch in said casing having switch operating mechanism including an operating handle which is located outside said casing, a vertically recipro'cable locking plate having a pivotal connection with said mechanism, said locking plate having a slot therein comprising a vertical portion and a rearwardly extended horizont-al portion, a fixed locking pin disposed in said slot. means constantly biasing said plate towards the front of said casing whereby to bring said locking pin in the horizontal portion of said slot, and means carried by the cover arranged to move said plate against its bias and bring said locking pin in the vertical portion of said slot.

12. VAn electric switch mechanism comprising an enclosing casing having an opening, a removable cover for said opening, a switch in said casing having switch operating mechanism including an operating handle which is located outside said casing, a vertically reopen position of said plate, a second pin car- Y ried by said cover which engages said locking f plate'in the closing movement ot said cover and urges it against its bias whereby to bring said first pin into the vertical portion of said slotsaid locking platealso having a second open top vertical slot, the opentop of which-is disposed beneath said cover pin in the closed position of said cover. Y

13. .An electric switch mechanism comprising an enclosing casing having an opening, a removable cover for said opening, a switch in said casing having switch operating mechanism including an operating handle which is located outside said casing, a vertically reciprocable locking plate having an'inv'erted L-shaped slot comprising a vertical portion anda rearwardly extendedy horizontal portion, affixed locking pin disposed in said slot,

means biasing said locking plate forwardly in the casing whereby to bring said pin in the horizontal portion of said slot in the lowermost position of said plate, a second pin carried by said cover arrangedto engage said plate during the closing movement of the cover, whereby to move said plate against its bias and bring said locking pin in the vertical portion of said slot, said locking plate alsok having a second vertical, open top slot therein, the open top of' which is disposed beneath said cover pin in the closed position .of said cover, and means operatively connecting-said locking plate with said switch operating mechanismV arranged ,to raise and lower said platepositively in response to switchV closing and opening .movements of said mechanisml a Y l Y V14. In combination an, enclosing casing having an opening, a removable cover for said opening, a remote controlled electrically operated circuit interrupter in said casing, a

manually controlled disconnecting switch electrically in series with saidV interrupter also contained in said casing, both said interrupter and VswitchV being accessible only through said opening, operating mechanism for said disconnecting switch including an operating handle locatedexternallyofv said casing', and means interlockingl said cover and the operating meclianismot said disconnecting switch arrangedto lock said cover against opening movement except'in the open position of said mechanism and alsofwhen said cover is open to lock said'mechanism lagainst Vclosing movement, saidfmeans including aY Y vertically reciprocable'locking plate which is `open when the cover is removed.`

15. An enclosed electric switch comprising an enclosing casing having-an entrance and a door for said entrance, an electric switch in said lcasing having switch operating mechanism, and locking mechanism -for said door and operating mechanism including a locklowing corresponding movements-of said opl erating mechanism havingmeans engaging said plate with a iXed part ofwsaid casing Ving plate movable in opposite directions folwhen the switch is open, whereby to hold the switch from closing, said platealso being engaged by said door and held thereby out of such engagement when the door `is closed, and said pla-te also having means which is engaged. with'a part of said closed door when the switch is closed and which holdsthe door against opening. Y Y I 1 16. An. enclosed electric switch 4comprising an, enclosing casinghaving a door, an electric switch in said casing having switchy 0perating mechanism, and locking mechanism for said'doorvand switch operating mechanism including a hub rotatable in opposite directions following corresponding movements of said operatingV mechanism, and ay locking plate loosely connected withand reciprocated bysaid hub, said plate having means ywhich is engaged with a fixed part of said casing only whenthe switch and also the door is open and which locks said switch mechanism against movement from a switch open position, and said locking plate also having meansV which is engaged by a part of the closeddoor and which is held by said'part out of'holding relation with said switch mechanism, and which plate also has means which engages ,said door and holds itin closed lposition when saidV switch mechanism is in switch closed position.. Y

17. An enclosed electric switch comprising an enclosing casing having a door, an elec-V tric switch in said casing having operating mechanism including an operating shaft,a ,hubV surrounding and having a driving connection with said shaft, and interlocking Y cover is open and which holds the operating mechanism against closing movement, said plate having means which is engaged by the closed door and which then holds said plate away from such locking engagement.

18. An enclosed electric'switch as defined in claim 17 wherein said casing has means which provides a rotatable support for said hub independently of said shaft, and said 1o shaft being loosely extended through said hub and having a removable driving connection therewith.

19. An enclosed electric switch as defined in claim 17 wherein said casing has means independent of said shaft in which said hub is rotatable, said shaft having an operating handle that has a detachable driving connection with said hub.

20. An enclosed electric switch as deiined 20 in claim 17 wherein said casing has means independent of said shaft in which said hub is rotatable, said hub having an abutment that extends through an opening of said casing, and said casing having a pair of spaced abutments that are alternately engaged by said hub-abutment.

21. An enclosed electric switch comprising an enclosing casing having an entrance, a cover for said entrance, an electric switch in said casing having a supporting plate that overlies a side wall of said casing and has a ledge that faces the entrance of said casing, a hub journalled in said plate behind said ledge, a locking plate loosely connected with said hub and lying between it and said ledge, means which urges said plate toward said ledge, switch operating mechanism including an operating shaft which is concentric and has a driving connection with said hub,

said plate having means which engages a fixed part of said supporting plate when said door and said switch are open and which holds said switch mechanism locked against closing movement, and said plate also having means which engages a part of the closed door and holds it against opening when said switch mechanism is in switch closed position.

22. An enclosed electric switch comprising an enclosing casing having an entrance, a

door closing said entrance, an electric switch in said casing having a supporting bracket that has an extension that overlies a side wall of said casing, a hub rotatable in said extension, switch operating mechanism, said extension having a pair of abutments extended through an opening in said side wall, and said hub having an abutment that alternately engages said extension-abutments, and an operating handle located mainly externally of said casing and having a driving connection with said operating mechanism and also with said hub.

In testimony whereof, I have signed my name to this specification.

HENRY P. PINKHAM. 

